340 X Head Valve Options

Ok, we need to slow way down and figure out what you are doing, and why. First, why do you think you need a 1.800 installed height? I run 1.72 or so and I NET .600 lift and that still gave me .090 to coil bind so I can shim .030 if I ever need to. You keep moving the tip of the valve up (towards the valve cover) by sinking the valve, or making the valve longer, just makes it harder to correct the rocker arm geometry. This is covered on the B3 racing site. At .620-650 lift you are pushing the stock valve gear to its limits.

Second, you always always always do the guides and seats BEFORE you port. Only run hard seats under the exhaust valve, not under the intake valve. It's a waste of money. The valve job establishes the percentage of bowl to valve among other things. If you aren't careful then cut the seats .030 smaller than finished diameter and then do the porting. You still have to finish the valve job and the port work without singing a seat.

Seems to me you are stuck on the 1.800 number and there is no need to get there. Do a good valve job, get the top cut .060-.100 wide and that should put you at 1.72 or so and that's good enough for .625 lift.

Didn't see the caliper pics. You already have all the installed height you need.

Hey thank man. I am listening.

The 1.80" installed height comes from stock specs for these springs as installed on a 6.1l hemi. I wanted to install them as close to stock height as I could so I could have the option to run as big of cam as possible. I see what your saying on geometry.

I also wanted as much install height as I can to avoid coil bind or excess spring pressure on the cam. I suppose that does not matter so much if I go with a roller cam.

Hardened seats are only going on exhaust side.

Sorry I'm a little confused what you meant on valve job and porting? So I need to have guides installed and then the valves roughed in to some extent, then port, then finish valve job and be done?

Appreciate all the help I can get! Thanks